title: The binding of haem and zinc in the 1.9 A X-ray structure of Escherichia coli bacterioferritin.
abstract: The crystal structure of Escherichia coli bacterioferritin has been solved to 1.9 A, and shows the symmetrical binding of a haem molecule on the local twofold axis between subunits and a pair of metal atoms bound to each subunit at the ferroxidase centre. These metals have been identified as zinc by the analysis of the structure and X-ray data and confirmed by microfocused proton-induced X-ray emission experiments. For the first time the haem has been shown to be linked to both the internal and the external environments via a cluster of waters positioned above the haem molecule.
authors.affiliation: School of Biosciences, Henry Wellcome Building for Biocatalysis, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK.
authors.forename: Simon C
authors.initials: SC
authors.lastname: Willies
authors.forename: Michail N
authors.initials: MN
authors.lastname: Isupov
authors.forename: Elspeth F
authors.initials: EF
authors.lastname: Garman
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Littlechild
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D001665:Binding Sites; D002570:Ceruloplasmin / Q000378:metabolism; D018360:Crystallography, X-Ray; D003573:Cytochrome b Group / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D004926:Escherichia coli / Q000737:chemistry*; D005293:Ferritins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D006418:Heme / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D011487:Protein Conformation; D015032:Zinc / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D003573:Cytochrome b Group; D006418:Heme; D005293:Ferritins; C018032:bacterioferritin; D002570:Ceruloplasmin; D015032:Zinc